#include <bits/stdc++.h>
using namespace std;

int main() {
  long N, M = 1e12, L = 1, F = 0;
  cin >> N;
  while (N) {
    L *= N, N--;
    if (L > M) L %= M, F = 1;
  }
  if (F) cout << setfill('0') << setw(12) << L % M <<"\n";
  else cout << L << "\n";
}